Safety attachment for elevators



C. LIDDICOAT.

SAFETY ATTACHMENT FOR ELEVATOHS. APPLlcATmN'FILw Nov. a, |919.

1 ,360,653. Patented Nov.130, 1920.

2 SHEETS-SHEET I.

C. LIDDICOAT.

V SAFETY ATTACHMENT FOR ELEVATORS. APPLTCATIQN FILED Nov. 8,1919.

Pfrlla'rl oFFlcE.

CALEB LIDDICOAT, OF ALBIA, IOWA.

SAFETY .ATTACHMENT FOR ELEVATORS.

Speccation of Letters Patent.

Patented N ov. 30, 1920.

Application led, November 8, `1919. Serial N0. 336,600.

To @ZZ w hom t may concern.'

Be it known that I, Carine Lmnroofrr, a citizen of the United States,residing at Albia, in the county of Monroe and State of iowa, haveinvented certain new and useful improvements in Safety Attachments forElevators, of which the following is a specification, reference beinghad to the accompanying drawings.

This invention relates to devices for preventing the accidental droppingof an elerator cage upon the breaking of an elevator cable or likehoisting means, and particularly to that class of devices whereinbreaking ofthe elevator cable causes certain guide engaging' wedges toshift from an ino 7erative to an operative position in engagement withthe vertical guides in the elevator shaft or well.

The general object of my invention is to provide a very simple andeffective device of this character which will operate automatically uponthe breaking of the elevator cable and which may be operated manuallywhen it is desired to hold the cage at any particular point in case ofdanger.

A further object is to improve upon the detailed construction andarrangement of parts of mechanism .of this character, and particularlyto improve'upon the construction and arrangement of the stops or blockswhich, in case of breakage, engage with the guides of the elevator, andprovide means for positively moving the stops into engagement with theguides, such means being of such character, however', that when thecable has been repaired, the lifting movement of the cable and elevatorwill cause the blocks to shift back into an inoperative position.

A further object is to provide a mechanism of this character in whichthe stopping means is not operated by springs or like devices liable toget out of order and become clogged or rusted so as to becomeinoperative. v

Other objects will appear in the course of the following description. y

My invention is illustrated in the accompanying drawings, wherein Figure1 is a vertical sectional view of an elevator cage having my safetyattachment applied thereto;

Fig. 2 is a fragmentary horizontal sectional view of the cage and guideson the line 2-2 of Fig. 1;

v F ig. 3 is a fragmentary vertical section through the casings of apair of stop blocks showing the stop blocks therein in inoperativeposition;

F ig. 4l is like view to Fig. 2 ing the stop blocks raised;

Fig. is a perspective view of one of the stop blocks;

`Fig. 6 is a fragment-ary elevation of one of the guides and thestopblock to show the manner in which the adjacent faces of the guide andstop block may be formed.

Referring to these figures, 10 designates an elevator cage of anysuitable form and construction, and 11 the guides between which theelevator cage operates. The cable 12 is connected to the four corners ofthe npper end of the elevator by downwardly divergent links 13 and 13a.The lower end of the cable 12 carries a short headed rod 14 havingthereon a weight 14a. The rod lei constitutes by itself a weight, andthe rod is guided by arms 15 pivoted to the cage and loosely engagedwith the rod 14. slackening or breaking of the cable 12 will cause theweighted rodl to drop.

lfiounted beneath the top of the cage are two levers 16 and 17, thelever 16 being formed at its inner end with a head 18 disposed beneaththe weight 15 and adapted to receive the impact of this weight when theweight drops, and the inner end of the lever 17 has a pivoted linkconnection with the adjacent extremity of the lever 16 that .30th leverswill move in unison. The levers are pivoted adjacent their outer ends bysuitable brackets and bearings 19, and the but show ,outer ends of theare provided with downwarcly ente-.ming rods 20 which, at their lowerends, have lateral, oppositely projecting extensions 21. These rods 20eX- tend down onthe inside faces of the elevator and the extensions 21project out beyond the lateral faces of the guides 11.

Disposed on each side of each guide 11 are the triangular casings 22which are rigidly attached tothe elevator cage. In each casing 22 is atriangular wedging block or stop 23 formed on its inner face withdownwardly extending teeth 24. The side faces of the guides 11 may beformed with upwardly ex tending teeth, as in Fig. 6, if desired, butunder normal circumstances these side faces will be left plain, as theteeth 24, upon the operation of the automatic stop, will bite into theguides sufliciently to prevent the elevator from dropping. Each block 23has a recess 25 upon one face which registers with an upwardly extendingslot 26 in the corresponding casing 22. A lug 27 on the adjacent end ofthe corresponding extension 21 extends through the slot 2G and engagesthe recess 25: It will be obvious now that if the rods 20 are pulledupward, the blocks 23 will also be pulled upward, and that the inclinedouter faces of the blocks will engage the outside inclined face of thecorresponding casing 32 and the blocks will be carried upward and inwardand toward the elevator guide, and that as soon as these blocks aremoved inward and become'engaged with the guide, the relative downwardmovement of the car will cause the blocks to be forced upward, wedgingthe blocks between the outer inclined faces of the casings 22 and the,elevator guides, causing` the faces of the blocks to bite into theguides. and stopping the car. This initial upward movement of the stopblocks 23 is secured when the cable 12 breaks by the dropping of theweighted rod 111 upon the inner end of the lever 16 which, beingconnected to the lever 17, causes a downward movement of the inner endof this lever 17 as well as the lever 16. This lifts the correspondingstop blocks into operative position to engage with the guides upon afurther downward movement of the elevator. f

In order to provide for manually controlling the movement of the stopblocks, I may elongate one of the levers, as the lever 17, to form ahandle 28, and if this handle be pulled downward, it will depress theinner ends of both levers 16 and 1'7 and raise the outer ends of thelevers. On the other hand, this handle 2S may be pushed upward vtothereby depress the outer ends of the levers after the blocks have beenthrown into operative engagement with the guides so as Yto depress theblocks 23, thus shifting them out of engagement with the guides, ifdesired, to permit the downward movement of the elevator. It will'beobvious that by intermittently putting the blocks out of operativeposition and into operative position, that the elevator may be allowedto move downward little by little through the elevator shaft;

It will be seen that the mechanism which I have devised is very simple,that it is not dependent upon'springs or like contrivances, or uponbolts projected by the springs into engagement with ratchet teeth on theguides,

lthe device may be operated by hand when desired and yet will operateautomatically when the cable breaks. Furthermore, the constructionpermitsthe wedging blocks 23 and the casings 22 to be made very strongso as to resist the strain to which they will be subjected when thewedging blocks are thrown into operative position. The greater theweight on the elevator cage tending to cause it to descend, the greaterwill be the grip of the stop blocks or wedging blocks on the elevatorguides, and furthermore the stoppage of the elevator will not be undulysudden because of the fact that the stop block must wedge into positionand gradually bind upon the guide.

Vhile I have illustrated a form of my invention which I have found to beparticularly effective in practical use, yet it will be obvious that theinvention might be changed in many ways without departing from thespirit of the invention.

I claim The combination with an elevator cage, guides therefor and acable operatively connected to the cage, of a rod suspended from saidcable, a weight on said rod, levers piv- Voted adjacent one of theirends to theV cage and having their other ends overlapping and pivoted toeach other for simultaneous movement beneath ythe rod, triangularcasings carried by the cage on each side of theguides, triangular stopblocks slidably disposed in each casing, each block having a recess inthe lower portion of one side, each of said casings havinga slot in oneside adapted to communicate with the recess in the block, verticallydisposed rods attached to the ends of said levers, the ends of each rodhaving a lateral extension adapted to laterally bridge the adjacentguides, the end portions of each extension being extended in rightangular relation to said extension and adapted to extend through theslot offthe adjacent casing, for engagement with the stop block, wherebysaid blocks are moved upwardly by the end portions of said extensionswithin the recesses of the blocksY when .the weight is released.

In testimony whereof I hereunto afx my signature.

CALEB LIDDICOAT.

